1. Field of the Invention
The present invention relates to a substrate processing apparatus and method for supplying a developer, a rinsing liquid and the like to substrates such as semiconductor wafers and glass substrates for liquid crystal display panels and for plasma display panels. And it relates especially to a developing apparatus and developing method for developing a thin resist film formed on those substrates and having a predetermined pattern exposed.
2. Description of the Background Art
Conventionally, developing apparatuses of this type comprise a developer supply nozzle having a slit developer discharge unit formed with an opening width equal to or greater than the width of a substrate, and a rinsing liquid supply nozzle having a slit rinsing liquid discharge unit formed with an opening width equal to or greater than the width of a substrate (refer to, for example, U.S. Pat. No. 6,092,937 and Japanese Patent Application Laid-open No. 10-340836).
Such developing apparatuses move the developer supply nozzle from one end of a substrate to the other to supply a developer to the entire upper surface of the substrate (this developer supply method is also called a slit scan developing method), and after the expiration of a predetermined time interval, move the rinsing liquid supply nozzle from one end of the substrate to the other with the same travel speed as the developer supply nozzle to supply a rinsing liquid to the entire upper surface of the substrate and thereby to stop development on the upper surface of the substrate.
In this case, making equal the travel speeds of the developer supply nozzle and the rinsing liquid supply nozzle carries the advantages that development time is approximately the same at each point on the upper surface of the substrate, thereby preventing unevenness in development, and that uniformity in the line width of a resist pattern after development can be improved.
However, in the above developing apparatuses, for reasons such as adhesion of undesirable matter to the discharge units and any possible defects resulting therefrom, the supply of a rinsing liquid from the slit discharge unit may not be uniform (for example, in amount and in velocity) along a discharge width of the discharge unit. The same can be said of the supply of a developer, but since especially a rinsing liquid needs to be passed over a layer of developer, the spacing between the rinsing liquid supply nozzle and the substrate becomes greater and, as a result, there is a greater likelihood that the supply of a rinsing liquid is not uniform.
In this case, since the rinsing liquid supply nozzle and the like are moved linearly from one end of the substrate to the other, a streak of area to which processing liquids were not supplied may remain along a direction of nozzle movement on the substrate, and therefore, the supply of a rinsing liquid and the like to the substrate may become nonuniform along the width of the substrate.